Cushion-brake



F. HYIVIANS.

CUSHION BRAKEa APPucATmN'HLmNov;21,1911.

1,3995560. Patented m '6, m1..

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UNrrED STATES rarsu'r OFFIQEf,

FREDERICK HYMANS, 0F GLEN' RIDGrE, NEW JERSEY, .dSSlGihlllt T Willi@ El'iEWdlh GOMPANY, OF JERSEY CTY, NEW JERSEY, d URWRATXN UIB NEW' il'lillthhlw.

CUSElN-HRME.

Patented Mec.. 6, lumi.,

application med November ai?, tai?. nei-ral iro. autant.

To 'all 'whom t may concern.'

Be it known that l, lnnnnnrcx Hifi/mias, a citizen oi the Netherlands, residing in Glen Ridge, in the county of Essex and State of New Jersey, have invented "a new and useful improvement in Cushion-Brakes, ot which the following is a specification.

lilly invention relates to bralre controlllng devices, and constitutes an improved means l'or controlling brakes lor a cushioned application, and for a quick release without injury to the brake releasing mechanism. This invention is especially adapted to use in electromagnetic bralres as employed in an elevator system,lalthough broad in scope and capable'ot a general application in any apparatus, wherein brake members are moved into and out ot irictional contact with one another.

ihn object ot my invention is the provision of an improved practical means toredecting a smooth and gradual application of braking torce, such means being appllcable to brakes in which the range oit action or the moving parts is very small.

A. further object is the provision in a cushion brake, ot means for maintaining, when once adjusted, a constant initial minimum braking action,'with subsequent gradual increase to maximum braking action, and means to insure an immediate application of the minimum braking action when the bralre applying apparatus is brought into operation, al1 independent oit conditions arising from wear on the braking members.

A further object is the provision in a cushion brake, comprising symmetrical parts operating in unison, oit' common adjusting means, each adjustment ot which will ad'eet at once the operations oi all such correspending parts. I l

A `further object is the provision in an electromagnetically released brake, oit means' for edecting a quick release ot the braking members followed by a retarded movement ot the electromagnet cores and parts connected therewith, to prevent a slamming together ot the cores. Other objects oit my invention will appear hereinafter.

'lhe accompanying drawing is a sectional elevation ot my invention embodied in a brake apparatus of well-known type. Cores l of electromagnets 2 are connected by pins 3 with pistons 4f, which pistons work in cylinders 5. Pins 6 connect pistons l with movable arms 7, `which arms are pivoted at dn auxiliary cylinder i9, preferably oli 4 relatively small bore, is provided in which is a piston 20, normally held seated by a spring 2l whose compression is adjustable by the manipulation oit a set screw 22 against a collar 23. The electromagnets with their cores, and the cylinders described are inclosed in a casing 2d, which is mounted on the frame 10 and serves as a reservoir *for oil or other Huid, the circulation oi which,

through the cylinders, controls the operation oi" the mechanism as hereinafter described.

@n opposite sides ol pistons l, in the cylinder 5, are cushion chambers 25 and 26, and in the cylinder i9 is an auxiliary cushion chamber 27 connected by pipe or assage 28 with the cushion chambers 26. Chamber 27' may be considered as a common extension ol chambers 26, Situated in the passage 28 is chech valve 29 operating tov allow :duid to dow unrestricted from the duid reservoir into but not out of chambers 26 and 27. Also situated in passage 26 is adjustable throttle valve 30, through which the lluid admitted to chambers 26 and 27 may be ejected by movement ot pistons d and 20 into the duid reservoir. Valves 29 and 30 may be oit various types, may be provided in any number to insure positive operation,

and may be situated at any place in passage 28 or in cushion chambers 26 and 27.

lin the walls oii cylinder 19 are apertures 31 connecting the interior ot the cylinder with the duid reservoir, and connecting chamber 27 with the fluid reservoir when `piston 20 has been moved away from its seat through approximately the distance at lin the particular construction here shown, l provide also aperture 36 to connect the inte-- rior oit cylinder 19 withthe Huid reservoir.

ln the walls ot cushion chambers 25, in

.cylinders 5, are apertures 32 connecting the chambers with the Huid reservoir, and so situated with regard to the path ol' travel ot lli titi

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i tons 4, into the fluid lreservoir.

' magnets 2 are act to bring with the friction pulley at the same timepistons 4 that the istons in moving in an inward direction w1 1 close the apertures before reaching their limits of travel. Chambers'. 25 are connected with each other by pi or passage 33 in which is situated check va ve 34 operating to allow fluid to flow unrestricted from the fiuid reservoir into but not out of chambers 25. Also situated in passage 33 is adjustable throttle valve 35 throughwhich thefluid admitted to `chambers 25 may be ejected, by movement of pis- Valves 34 may be and 35 may be of various types,

' positive provided in any number to insure operation, and may be situated at in assage 33 or in chambers 25.

he accompanying drawin shows the apparatus at the completion o the brake alpplying o eration, with electromagnets ener zedp and maximum braking .force a plier?.1 A complete cycle of operation of t e ap aratus takes place as follows.

gVhen electromagnets 2 are energized, cores 1 are drawn inward carrying with them pistons 4 in cylinders 5, and releasing the brake shoes from contact w1th the frlction, pulley. The fluid in cushion chambers 25 is expelled through apertures 32 until the pistons have traveled sufficient distance toclose the apertures after which the fluid is ejected from the chambers through passage 33 and throttle valve 35 until the limits of travel of the pistons are vreached by the meeting of the electromagnet cores. The rate o f travel of pistons 1 after apertures 32 have been closed may be controlled by adjusting throttle valve 35..

The results of the operation described is an initial unretarded movement of cores 1 and pistons 4, followed by a retardation in the movement of the parts at the completion of the stroke to prevent a slamming together of the cores. It has heretofore been the practice to retard the movement of the cores through their entire brake-releasing stroke, with the resulting disadvantage of a slow release of the brake shoes, and, in alternatin current brakes, of prolonging the perio during which the magnet takes a large starting current from the line. In my invention, however, the retardation occurs at a point very near the completion of the stroke, thereby permitting a quick release ofV the brake shoes. Furthermore, the air gap betr-een the magnet cores rapidly decreases, and at the time tion occurs the same will be so small as not to entail an appreciable excess of current above that required when the cores are sealed together.

Now to apply the braking force, electrodenergized and springs 16 the brake shoes into contact moving through members 14, levers 9, and

any place that the retardaarms 7, the pistons 4, in an outward direction, and expelling fiuid from chambers 26 through passages 28 into chamber 27 of cylinder 19, so forcing piston 20 away from its seat a ainst the compression of spring 21. Thus t e greater part of the force of spring 16 is expended in so actuatin pistons 4 and 20 with the result that the rake shoes are brought immediately but with greatly reduced pressure into contact with the friction pulley. The compression of spring 2l now acts to return piston 20 to its seat, which is accomplished by ejecting fiuid through throttle valve 30. As the fluid is so ejected the compression of spring 21 decreases with 'a resultant partial increase of pressure from spi-ings 16 on the brake shoes until piston 20 is again seated, at which time no further resistance is offered to the action of springs 16, which now exert their full maximum pressure on the brake shoes.

It will be seen that with wear on the bilake shoes and friction pulley, and a resultant increase of air gap between the magnet cores, the distance of travel of pistons 4 and the volume of fiuid forced into cylinder 19 will become correspondingly geaten The result of this condition would to prolong the cushioning action to too great an extent, and with increased wear would further result in a delay in the initial application of the brake shoes, necessitating frequent adjustments to maintain a constant braking action. tion, I have provided apertures 31 in cylinder 19 in order that when piston 20 has en moved through approximately a distance a the cushion chamber 27 will become connected with the fiuid reservoir, and all fluid forced into chamber 27 thereafter will escape throu h the apertures without rtlier moving piston 20. Aperture 36 is rovidedrto insure a free circulation of fluid hind piston 20. I thus limit the amount of force with which spring 2l is capable of resisting the action of spring 16 by limiting the stroke of piston 20, and by so doing provide an initial braking action constant when once adjusted, followed by a rate of increase to maximum braking action, also constant when once adjusted, independent of conditions arising from wear on the brakinfmembers.

djustment of the initial minimum brake pressure may be made by varying, through the adjusting means provided, the relative forces exerted by springs 16 and spring 21, while the time occupied inpassing from minimum to maximum pressure may be varied at will according to operating require` ments by adjusting throttle valve 30.

By connecting chambers 25 through pas- To meet this condi- `Sage 33 and furnishing throttle valve 35 to Lacanau each adjustment of which affects at once and alike the brake releasing operation of the corresponding parts on both sides of the apparatus. Also by connecting chambers 2 5 through passage 28, furnishin a common extension in chamber 27, and urnishing throttle valve 30 to control the ejection of fluid from both chambers 26; and

further. `by furnishing set screw 22 to vary the compression of spring 2l, I provide common adjusting means, each adjustment of which affects at once and alike the brake applying operation of the corresponding parts on both sides of the apparatus. rlhus it will be seen that in providing in my invention the common adjusting means described, I insure an operation in unison of all corresponding parts.

In former types of similar cushion brakes, the operation in cushioning the brake application has been dependent upon springs acting against auxiliary pistons in the main cylinders, which pistons traveled only through the distance of movementA of the magnet cores. In most brakes this distance is so small that it has been diilicult to obtain a satisfactory positive spring action therein. 'lo overcome. this detect l utilize the movement of the pistons'in the main cylinders to torce lluid into a relatively small cylinder against a piston Whose distance of travel will be greater than that of the main pistons so long as its area is less than the Sum of the areas of the main pistons. Thus the distance of travel of the auxiliary piston may be made sufficiently great to compress a spring so that it will react` in satisfactory manner and cause a positive cushioning action. Auxiliary cylinders might be provided in any number and might be provided for each main cylinder individually, but in the preferred arrangement here shown the desired results are accomplished with a minimum number ot parts, and tlie coperation ofthe main pistons is insured.

Obviously those skilled in the art may make various changes in the details, arrangements, and number of parts Without departing from the spirit and scope of my invention, and I desire therefore not to be limited to the construction herein described.

I claim 1. In combination, a brake, brake applying means, main cylinders, p1stons movable therein to control the operation of the brake applying means for a gradual operation, an auxiliary cylinder of smaller bore than the said cylinders, and a piston movable therein to regulate the movement of the main pistons, and pipes connecting the main and auxiliary cylinders.

2. In combination, a brake, brakeappl -k ing means, main cylinders, pistons movab e therein to control the brake appl ing means for a gradual operation, an aux` 'ary cylinder of smaller bore than the said cylinders, a piston movable therein to regulate the movement ot the main pistons, pipes connecting the main and auxiliary cylinders, and means to control the operation ot the piston in the auxiliary cylinder.

3.. ln combination, a brake, brake applying means, main cylinders, pistons movable therein to control the brake applying means for a gradual operation, an auxiliary cylinder of smaller bore than the said cylinders, a piston movable therein to regulate the movement of the main istons, pipes connecting j the main and aux' iary cylinders, means to control tlie operation ot the piston in the auxiliary cylinder and means to limit the stroke of the same.

4. In combination, a brake, brake applying means, main cylinders, pistons movable therein to control the operation ot the brake appl in means, an auxiliar c linder el' smal er lore than the said cy in ers, a piston movable therein to regulate the movement of the main pistons, a reservoir to contain a fluid to regulate the movement ot the pistons, fluid passages tor the lluid to pass between the main cylinders and the auxiliary` cylinder, restricted passages between the cylinders and the reservoir lor the duid to pass, passages between the auxiliary cylinder and the reservoir tor the duid to ass, and means to limit the stroke ol the piston in the auxiliarycylinder, and means to regulate the movement oil the said piston.

5. ln combination, a brake, brake applying means, main cylinders, pistons movable `therein to control the brake applying means,

an auxiliary c linder ot smaller bore than the main cylin ers, a piston movable therein to regulate the movement ot the main pistons, pipes connecting the main and auxiliary cylinders, a seat tor the piston in the auxiliary cylinder, means to constrain the said piston in its seat, means to adjust the constraining means, and means to regulate the o eration ot the pistons.

6. In a cushion brake, means, comprising a main cylinder and a piston movable therein to control the brake applying means, an auxiliary `cylinder and a piston therein, pipes connecting the cylinders, a spring beind the piston in the auxiliary cylinder, adapted to be compressed by the iston, and a discharge aperture in the auxi iary cylinder behind the piston, whereby a constant cushioning action in brake application is maintained independent of wear on the parts of the brake.

In testimony whereof, I have signed my name to this speciiication in the presence of y two subscribing` witnesses.

Eiinns'r L. Gam, Jr., Hazan R. Garan,

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